Fort Hartenberg: A Nineteenth-Century Fortification of Mainz
Site at a Glance
- Rating
- 4.3
- Popularity
- Low
- Country
- Germany
- Primary era
- Modern
- External website
- Open
- Eras represented
- Modern
- Civilizations
- German
- Site type
- Military
- Remains
- Fort
On this page8 sections
History
Fort Hartenberg is a nineteenth-century German fortification in Mainz, Germany, built during the third fortification phase of Mainz Fortress and incorporated into the Rheingau Wall. After the Congress of Vienna, the 1814–1815 settlement that reorganized Europe after the Napoleonic Wars, Mainz was reorganized as a fortress of the German Confederation, the political association of German states created by that settlement. Fort Hartenberg formed part of this defensive system, which was intended to protect Mainz’s Neustadt from cannon fire.
Fortress Reorganization
The fort belonged to the nineteenth-century expansion and reorganization of Mainz’s defenses. Together with the neighboring Fort Hartmühl, it occupied a place within the wider fortification landscape around the city. Its defensive role was linked to the Rheingau Wall, a nineteenth-century defensive belt forming part of Mainz Fortress.
Demolition and Emergency Housing
After the First World War, the Treaty of Versailles required changes to German military fortifications. At the direction of France, the victorious power, Fort Hartenberg and Fort Hartmühl were partially demolished in the early 1920s. Several vaulted spaces initially survived this process. During the late 1940s, after homes had been destroyed in the Second World War, people used some of these spaces as emergency housing. Interior rooms were even finished with wallpaper patterns. The remaining structures were later covered over, leaving some portions underground and normally inaccessible.
Schools, Redevelopment, and Archaeology
As the Hartenberg district expanded from the late 1950s, the Hartenberg School was constructed from 1965 almost directly above the former fort and opened in summer 1968. The building also housed Mainz III Secondary School from 1973 to 1978, after which that school moved to Fritz-Strassmann Secondary School in Hechtsheim. Following the conversion of a nearby US military housing area into the publicly accessible Martin-Luther-King-Park residential area in the mid-1990s, the elementary school moved there and the former building was taken over by the Peter Jordan School, a special-needs school. That school left in 2010 because the building required renovation. In 2013, the Mainz city council decided to relocate it permanently to the Am Gleisberg site because financing the renovation was difficult, and in 2014 it approved demolition of the building and housing redevelopment on the land. The cultural initiative Peng used the school from April 2014 to November 2015, while the building also provided refugee accommodation from December 2014 until mid- or late 2016. Test drilling and initial excavation followed on the football field, and the school buildings were demolished in 2018. Excavation for the housing project then exposed extensive parts of Fort Hartenberg and clarified its former dimensions. The discovery of underground mining galleries led to a three-month construction halt from September 2019, allowing archaeologists to survey and document the remains before sections beneath the planned housing and underground garage were removed.
Remains
Overall Plan and Surviving Masonry
Fort Hartenberg was organized around a central reduit, a fortified keep, whose plan was pentagonal. Its outer walls followed an essentially pentagonal layout, and the complete installation measured just under 200 metres in diameter. The fort’s remains lie within the grounds of present-day Hartenberg Park, east of the basketball court. Only a few walls remain above ground east of the basketball hoop, while other vaulted and underground portions lie partly beneath later ground layers. The reduit was uncovered in 2017, archaeologically recorded, and subsequently removed by excavation machinery. Surviving above-ground masonry and the fort’s eastern cavalier remain identifiable in the park, although other parts have been buried or removed.
Eastern Cavalier and Fort Connection
The eastern cavalier, a raised fortification intended to provide elevated artillery or defensive fire, faced the valley of present-day Wallstrasse and closed the fortification. This structure remains well preserved. Fort Hartenberg was also linked to the similarly large Fort Hartmühl to the north by a connecting structure approximately 300 metres long. The passage was designed to let troops move without being observed and ran approximately along the route of the asphalted main path in today’s park. The two forts remain separate archaeological areas: Fort Hartenberg lies east of the basketball court, while Fort Hartmühl lies north of the water features.
Underground Mining Galleries
The fort’s mining galleries extended mainly westward at shallow depth. These low underground passages were intended for the placement and detonation of explosive charges beneath or near besieging forces that had survived bombardment. They were therefore part of the fort’s defensive system, rather than routes for troop movement. The galleries came to light during excavation for the housing development and prompted archaeological survey before parts beneath the planned buildings and underground garage were removed. Some subterranean remains are still partly preserved beneath later ground layers, but they are generally not publicly accessible.
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